1. Field of the Invention
This invention relates generally to light sensors, and more particularly to integrating light systems that provide an indication of the total amount of light sensed over a predetermined time interval.
2. Description of the Prior Art
Various light sensing systems, including integrating systems, are known; however, systems capable of operating at low light levels typically require preamplifiers between the light sensing device and the integrating amplifier. Such preamplifiers are disadvantageous in that they have offset and drift problems that must be compensated, thereby resulting in a fairly complex and expensive design. In addition, systems that use a dual-slope integrator for integrating the output of the sensor generally require switching circuitry for alternately connecting and disconnecting the sensor from the integrator. Such switching devices further add to the complexity of the system and cause further drift and voltage offset problems.